CN113374747A - Design method of swash plate plunger type hydraulic transformer buffering structure - Google Patents
Design method of swash plate plunger type hydraulic transformer buffering structure Download PDFInfo
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- CN113374747A CN113374747A CN202110382397.5A CN202110382397A CN113374747A CN 113374747 A CN113374747 A CN 113374747A CN 202110382397 A CN202110382397 A CN 202110382397A CN 113374747 A CN113374747 A CN 113374747A
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- 238000000034 method Methods 0.000 title claims abstract description 37
- 238000013461 design Methods 0.000 title claims description 15
- 230000003139 buffering effect Effects 0.000 title claims description 11
- 230000009466 transformation Effects 0.000 claims abstract description 20
- 230000008569 process Effects 0.000 claims abstract description 14
- 230000008859 change Effects 0.000 claims abstract description 10
- 230000000630 rising effect Effects 0.000 claims abstract description 6
- 238000004088 simulation Methods 0.000 claims abstract description 5
- 230000006837 decompression Effects 0.000 claims abstract description 4
- 230000033001 locomotion Effects 0.000 claims description 7
- 230000003247 decreasing effect Effects 0.000 claims description 3
- 238000009795 derivation Methods 0.000 claims description 3
- 238000010586 diagram Methods 0.000 claims description 3
- 230000009467 reduction Effects 0.000 claims description 3
- 238000005516 engineering process Methods 0.000 claims description 2
- 230000001052 transient effect Effects 0.000 claims description 2
- 230000007704 transition Effects 0.000 claims description 2
- 239000003921 oil Substances 0.000 claims 12
- 239000010720 hydraulic oil Substances 0.000 claims 1
- 238000006467 substitution reaction Methods 0.000 claims 1
- 230000000694 effects Effects 0.000 description 4
- 238000004891 communication Methods 0.000 description 2
- NAWXUBYGYWOOIX-SFHVURJKSA-N (2s)-2-[[4-[2-(2,4-diaminoquinazolin-6-yl)ethyl]benzoyl]amino]-4-methylidenepentanedioic acid Chemical compound C1=CC2=NC(N)=NC(N)=C2C=C1CCC1=CC=C(C(=O)N[C@@H](CC(=C)C(O)=O)C(O)=O)C=C1 NAWXUBYGYWOOIX-SFHVURJKSA-N 0.000 description 1
- 230000006978 adaptation Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B3/00—Intensifiers or fluid-pressure converters, e.g. pressure exchangers; Conveying pressure from one fluid system to another, without contact between the fluids
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- Engineering & Computer Science (AREA)
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Abstract
The invention discloses a method for designing a buffer structure of a swash plate plunger type hydraulic transformer, which comprises the following steps: 1. establishing an angle of interest
The oil pressure gradient in the plunger cavity; 2. deducing an incremental equation to obtain the oil pressure change delta p1And Δ p2(ii) a 3. Taking different envelope angles of buffer structure
To obtain Δ p1Within a variable voltage angle interval of [0 DEG, 120 DEG ]]The inner pressure change curve selects a proper envelope angle of the buffer structure according to the rated pressure and the maximum transformation ratio
The pressure of the oil source; 4. according to the pre-decompression interval from the notch A to the notch T, the size of a buffer structure in the pre-decompression process is solved; 5. according to the advance of notches T to BA boosting interval, wherein the size of a buffer structure in the pre-boosting process is solved; 6. according to the pre-rising/reducing interval from the notch B to the notch A in the transformation angle, the size of the buffer structure in the pre-rising/reducing process is solved; 7. CFD simulation analysis of the swash plate plunger type hydraulic transformer.
Description
Technical Field
The invention relates to the technical field of hydromechanics, and particularly discloses a design method of a swash plate plunger type hydraulic transformer buffer structure.
Background
The swash plate plunger type hydraulic transformer is a key element of a constant voltage network secondary regulation system, and in order to relieve the problems of noise and vibration existing in the working process of the hydraulic transformer, the internal pressure impact of the hydraulic transformer can be relieved by establishing a buffer structure on the valve plate, so that the noise and the vibration are solved. However, the pressure impact inside the swash plate plunger type hydraulic transformer can change along with the change of the transformation angle, so that the existing buffer structure design method cannot effectively relieve the pressure impact inside the hydraulic transformer in the transformation angle change interval [0 degrees and 120 degrees ]. Therefore, how to design the buffer structure of the swash plate plunger type hydraulic transformer is a research hotspot in the academic field at present, and has important engineering application value for making up the defects of the existing design method.
Disclosure of Invention
The technical problem to be solved by the invention is as follows: the method solves the problem that the buffer structure can not effectively relieve the internal pressure impact of the novel hydraulic transformer in a variable-voltage angle interval of [0 degrees and 120 degrees ], provides a design method of the swash plate plunger type hydraulic transformer buffer structure based on an incremental equation of oil pressure gradient in a plunger cavity, and can realize the relief of the internal pressure impact of the swash plate plunger type hydraulic transformer at any variable-voltage angle.
The technical scheme adopted by the invention for solving the technical problems is as follows: a design method of a swash plate plunger type hydraulic transformer buffering structure comprises the following steps:
the method comprises the following steps: the oil pressure gradient in the plunger cavity is deduced according to a volume control method, and because the volume efficiency of the plunger element is high and the leakage is small, after the leakage is ignored, only the influence caused by the movement of the plunger and the communication between the plunger and the buffer structure is considered, and the angle can be obtained
The gradient of the oil pressure in the plunger cavity:
step two: the incremental equation obtained by the derivation of the oil pressure gradient in the plunger cavity is
Further comprises
Step three: taking envelope angles of buffer structures of different sizes
To obtain Δ p1Within a variable voltage angle interval of [0 DEG, 120 DEG ]]The inner pressure change curve selects a proper buffer structure envelope angle according to the rated pressure and the maximum transformation ratio of the hydraulic transformer
The oil source pressure.
Step four: according to the envelope angle of the buffer structure obtained in the third step
Designing the size of a buffer structure, and solving to enable delta p according to the pre-reduction interval from the notch A to the notch T1And Δ p2The size of the buffer structure for completing the pre-decompression process in advance is matched.
Step five: similar to step four, the solution enables Δ p according to the pre-boosting interval from notch T to notch B1And Δ p2The size of the buffer structure for completing the pre-boosting process in advance is matched.
Step six: similar to the fifth step, according to the pre-rising/decreasing interval from the notch B to the notch A in the transformation angle, the solution can enable the delta p1And Δ p2The size of the buffer structure for completing the pre-rising/pressure-reducing process in advance is matched.
Step seven: CFD simulation analysis of the swash plate plunger type hydraulic transformer.
The coefficients and parameters given in the above-described embodiments are provided to enable a person skilled in the art to make or use the invention, and the invention is not limited to the values given in the foregoing disclosure, but various modifications and adaptations can be made by a person skilled in the art without departing from the inventive concept of the present invention, and therefore the scope of protection of the invention is not limited by the above-described embodiments but should be accorded the widest scope of the inventive features set forth in the appended claims.
Description of the drawings:
FIG. 1 is a flow chart of a design method of a swash plate plunger type hydraulic transformer buffering structure.
Fig. 2 is a block diagram of a port plate.
Fig. 3 is a graph of the change in oil pressure in the plunger cavity caused by the plunger movement.
FIG. 4 is a comparison of the buffering effect curves of different buffer holes of notches A-T.
FIG. 5 is a graph comparing the buffering effect curves of different buffer holes of notches T-B.
FIG. 6 is a comparison graph of buffering effect curves of different buffering holes of notches B-A in a variable pressure angle interval [0 degrees, 60 degrees ].
FIG. 7 is a comparison graph of buffering effect curves of different buffer holes of notches B-A in a variable pressure angle interval [60 degrees, 101 degrees ].
FIG. 8 is a three-dimensional model of a swash plate plunger type hydraulic transformer.
FIG. 9 fluid model of a swash plate piston hydraulic transformer.
FIG. 10 Hydraulic Transformer grid model.
Fig. 11 shows the oil mass average pressure curve in the plunger cavity when the transformation angle δ is 30 °.
Fig. 12 shows the oil mass average pressure curve in the plunger cavity when the transformation angle δ is 60 °.
Fig. 13 shows the oil mass average pressure curve in the plunger cavity when the transformation angle δ is 90 °.
Fig. 14 shows the oil mass average pressure curve in the plunger cavity when the transformation angle delta is 101 deg..
The specific implementation mode is as follows:
the following describes in detail embodiments of the present invention with reference to the accompanying drawings.
The invention discloses a method for designing a buffer structure of a swash plate plunger type hydraulic transformer, which specifically comprises the following steps:
the method comprises the following steps: the oil pressure gradient in the plunger cavity is deduced according to a volume control method, and because the volume efficiency of the plunger element is high and the leakage is small, after the leakage is ignored, only the influence caused by the movement of the plunger and the communication between the plunger and the buffer structure is considered, and the angle can be obtained
The oil pressure in the plunger cavity has a gradient of
Wherein: p is the pressure (Pa) of oil in the plunger cavity; beta is aeThe elastic modulus (Pa) of the oil liquid; vminIs the minimum volume (m) of oil in the plunger cavity3)；SAIs the plunger area (m)2) (ii) a R is the plunger distribution circle radius (m); β is a swash plate angle (°);
an angle (°) by which the plunger rotates from the bottom dead center to a pre-ascent/descent initial position; cqA flow coefficient of the buffer structure; delta p is the oil pressure difference (Pa) between two adjacent notches; rho is the oil density (kg/m)3) (ii) a n is the rotating speed (r/min) of the swash plate plunger type hydraulic transformer; s0Is the minimum flow cross section area (m) of the buffer structure2)。
Step two: the incremental equation obtained by the derivation of the oil pressure gradient in the plunger cavity is
Further comprises
Wherein: Δ p1The pressure of oil in the plunger cavity is changed due to the movement of the plunger; Δ p2The oil pressure in the plunger cavity changes due to the buffer structure.
Step three: taking envelope angles of buffer structures of different sizes
And substituted into
In the interval [0 DEG, 120 DEG ]]Formula (3) of time at [0 °, 120 °]Within the interval, | Δ p1I is less than the rated pressure of the swash plate plunger type hydraulic transformer, and accordingly, a proper buffer structure envelope angle is selected
And selecting the oil source pressure according to the maximum transformation ratio of the swash plate plunger type hydraulic transformer, wherein the product of the maximum transformation ratio and the oil source pressure is not greater than the rated pressure of the swash plate plunger type hydraulic transformer.
Step four: according to the envelope angle of the buffer structure obtained in the third step
Designing the size of a buffer structure, wherein delta p exists in a pre-reduction interval from notch A to notch T1＜0，Δp2> 0, in order to make Δ p2Can be reacted with Δ p1In combination with the pre-depressurization process, there are
Wherein: Δ pA-TIs the difference between the oil pressure at notch T and notch a.
Further comprises
And substituting different buffer structure sizes into the formula (6) to obtain the buffer structure size capable of meeting the condition, obtaining a buffer effect graph (figure 4) of the notch A-T buffer hole under different angles by utilizing Matlab software, and selecting according to actual conditions to determine the optimal buffer structure.
Step five: similar to step four, there is Δ p in the pre-boosting interval from notch T to notch B1＞0，Δp2< 0, in order to make Δ p2Can be reacted with Δ p1Cooperate with the pre-boosting process to be completed in advance, have
Wherein: Δ pT-BThe difference between the oil pressure at notch B and notch T.
Further comprises
Substituting different buffer structure sizes into the formula (8) to obtain the buffer structure size capable of meeting the conditions, obtaining a T-B buffer hole buffer effect graph (figure 5) of the notch under different angles by utilizing Matlab software, and then selecting according to actual conditions to determine the optimal buffer structure.
Step six: the angle between the notch B and the notch A is within the variable pressure angle range of 0 degrees and 60 degrees]With pre-boosting interval Δ p1＞0，Δp2< 0, in order to make Δ p2Can be reacted with Δ p1Cooperate with the pre-boosting process to be completed in advance, have
Wherein: Δ pB-AIs the difference between the oil pressure at notch a and notch B.
Further comprises
Substituting different buffer structure sizes into the formula (10) to obtain the buffer structure size capable of meeting the condition, and obtaining a buffer effect graph of the notch B-A buffer hole under different transformation angles by utilizing Matlab software (figure 6).
The distance from notch B to notch A is in the variable voltage range of [60 degrees, 120 degrees ]]With a pre-decreasing interval Δ p1＜0，Δp2> 0, in order to make Δ p2Can be reacted with Δ p1In combination with the pre-depressurization process, there are
Wherein: Δ pB-AIs the difference between the oil pressure at notch a and notch B.
Further comprises
Substituting different buffer structure sizes into the formula (12) to obtain the buffer structure size capable of meeting the condition, and obtaining buffer effect graphs (shown in figure 7) of different buffer hole diameters of notches B-A under different transformation angles by utilizing Matlab software. And further selecting the size of the buffer structure which can meet the conditions in the variable-pressure angle interval [0 degrees and 120 degrees ], and selecting according to the actual condition to determine the optimal buffer structure.
Step seven: according to the structural size of each buffer hole, a flow field model of the swash plate plunger type hydraulic transformer is subjected to three-dimensional modeling through UG software, and the hydraulic transformer is subjected to grid division by using ANSYS software based on a user-defined function and a dynamic grid technology, as shown in FIG. 10.
Step eight: simulation is carried out on the transient state of the plunger in transition among different notches based on FLUENT software, and the pressure distribution diagram of the flow field of the hydraulic transformer in high-speed work is finally obtained by controlling the motion state of the plunger (figures 11-14).
Claims (6)
1. A design method of a swash plate plunger type hydraulic transformer buffer structure is realized according to the following steps:
the method comprises the following steps: and (4) deducing an oil pressure gradient equation in the plunger cavity according to a volume control method.
Step two: and (4) deriving an incremental equation from an oil pressure gradient equation in the plunger cavity. Further obtaining the oil pressure change deltap in the plunger cavity caused by the movement of the plunger1And buffer node configured plunger cavity oil hydraulic pressure change delta p2。
Step three: taking envelope angles of buffer structures of different sizes
To obtain Δ p1Within a variable voltage angle interval of [0 DEG, 120 DEG ]]The inner pressure change curve selects a proper buffer structure envelope angle according to the rated pressure and the maximum transformation ratio of the hydraulic transformer
The oil source pressure.
Step four: according to the envelope angle of the buffer structure obtained in the third step
Designing the size of a buffer structure, and solving to enable delta p according to the pre-reduction interval from the notch A to the notch T1And Δ p2The size of the buffer structure for completing the pre-decompression process in advance is matched.
Step five: similar to step four, the solution enables Δ p according to the pre-boosting interval from notch T to notch B1And Δ p2The size of the buffer structure for completing the pre-boosting process in advance is matched.
Step six: similar to the fifth step, according to the pre-rising/decreasing interval from the notch B to the notch A in the transformation angle, the solution can enable the delta p1And Δ p2The size of the buffer structure for completing the pre-rising/pressure-reducing process in advance is matched.
Step seven: CFD simulation analysis of the swash plate plunger type hydraulic transformer.
2. The design method of the buffering structure of the swash plate plunger type hydraulic transformer as claimed in claim 1, wherein the derivation is performed with respect to the angle
The gradient equation of the oil pressure in the plunger cavity is as follows:
wherein, VminIs the minimum volume (m) of oil in the plunger cavity3)，Vmin＝6.22×10-6m3；SAIs the plunger area (m)2)，SA＝πd2(ii)/4; r is the radius (m) of the plunger distribution circle, and R is 0.0335 m; β is a swash angle (°), and β is 18 °. CqTaking C as flow coefficient of buffer structureq＝0.82；S0Is the minimum flow cross section area (m) of the buffer structure2) (ii) a Rho is the oil density (kg/m)3) Taking the oil density of No. 32 antiwear hydraulic oil, rho is 870kg/m3。
3. The design method of the buffer structure of the swash plate plunger type hydraulic transformer as claimed in claim 2, wherein the incremental equation derived from the oil pressure gradient in the plunger cavity is as follows:
further comprises
4. The design method of the buffer structure of the swash plate plunger type hydraulic transformer as claimed in claim 3, wherein the value substitution is βe＝7×108Pa；V＝-6m3min；SA＝2.27×10-4m2；R＝0.0335m；β＝18°；Cq＝0.72；ρ＝870kg/m3(ii) a n is 1000 r/min. Taking envelope angles of buffer structures of different sizes
And substituted into
In the interval [0 DEG, 120 DEG ]]Formula (3) of time at [0 °, 120 °]Within the interval, | Δ p1The pressure is less than 40MPa of rated pressure of the swash plate plunger type hydraulic transformer, and accordingly, a proper buffer structure envelope angle is selected
The maximum transformation ratio is 5 degrees, the product of the maximum transformation ratio and the oil source pressure is not larger than the rated pressure of the swash plate plunger type hydraulic transformer, the maximum transformation ratio of the swash plate plunger type hydraulic transformer is 3, the maximum transformation ratio is 4 for safety, and therefore the oil source pressure is selected to be 8 MPa. When the buffer structure is a buffer hole with constant flow cross-sectional area and diameter d, there are
Substituting into corresponding condition formula to obtain the buffer structure size satisfying the condition, and further selecting the buffer structure size capable of changing the voltage angle interval [0 °, 120 ° ]]And selecting the size of the buffer structure meeting the conditions according to the actual condition to determine the optimal buffer structure.
5. The design method of the buffer structure of the swash plate plunger type hydraulic transformer as claimed in claim 4, wherein a flow field model of the swash plate plunger type hydraulic transformer is three-dimensionally modeled by UG software according to the structural size of each buffer hole, and ANSYS software is used for meshing the hydraulic transformer based on a user-defined function and a moving mesh technology.
6. The design method of the buffering structure of the swash plate plunger type hydraulic transformer as claimed in claim 5, wherein simulation is performed on transient state of the plunger in transition between different notches based on FLUENT software, and the pressure distribution diagram of the flow field of the hydraulic transformer in high-speed operation is finally obtained by controlling the motion state of the plunger.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114580116A (en) * | 2022-03-16 | 2022-06-03 | 北京建筑大学 | Damping structure design method for improving pressure impact characteristic of hydraulic transformer |
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2021
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